So the issue at hand; My 9-7x seems to have AWD grip when I'm doing above 25mph. But I only have RWD when I'm just starting off, even if the rear wheels spin. But there's no reaction happening. To test this, I stopped on moderately snowy unpaved hill. The rear wheels spun, and the fronts did not engage, I had to back down the hill onto dry pavement in order to get started. Now last week when I was changing my oil, I put it in drive on the lift, and the front wheels did spin, but the "Service 4WD" light came on, and went off with the next ignition cycle. Now, I figure the Transfer Case and it's associated hardware (Motor and TCCM) are okay since the front wheels had power. I'm thinking a wheel sensor perhaps, but I feel like that would set a code and my dash is clear. I'm beyond stumped about this, and for that matter I'm broke too. I'm really at my wits end with this, my mechanic says the front diff might be bad, but I've heard very few cases of front diff failure. I am unsure of the truck's service history before 90k miles.

Was done at 92k. I'm at 132k at the moment. It was done by a GM dealer before I bought the vehicle. It was serviced there pretty much its entire life. I have a meticulous service history for it (one of the major reasons I chose to buy it)

therealsethallen wrote:Was done at 92k. I'm at 132k at the moment. It was done by a GM dealer before I bought the vehicle. It was serviced there pretty much its entire life. I have a meticulous service history for it (one of the major reasons I chose to buy it)

If you have not changed the fluid in the transfer case every 50k is possible most likely the clutches in the transfer case are worn out. IIRC in a AWD system there is no switch and normally from what I have read in AWD there is a 5% load up front all the time and adjust up higher % as the rear wheels slip. So if the clutches are worn out... You get the picture.

I'm looking into replacement NVG126 cases now. Rebuilding is possible but I can't have my truck hogging up a lift. Found one for $200 with about the same millage pretty close to me. I'm not going to buy it without knowing they'll take it back if it's not my issue. But first, I'll try some fresh Auto-Trak II and see what that does. Fortunately I'm about due for an oil change anyways so I'll just do it then.

It's my understanding that all of GMs encoder motors from 1999-07 (The GMT800&360/70) had pretty high fail points. I got a really good offer on one. My local junkyard that I do gobs of business with offered me a TC from a Rainer for $200! With 66k on the clock. But they sold the shift motor off it already so I'd need to hunt one down. I'm going to do a TC fluid change with my next oil change first.

It's my understanding that all of GMs encoder motors from 1999-07 (The GMT800&360/70) had pretty high fail points. I got a really good offer on one. My local junkyard that I do gobs of business with offered me a TC from a Rainer for $200! With 66k on the clock. But they sold the shift motor off it already so I'd need to hunt one down. I'm going to do a TC fluid change with my next oil change first.

navigator wrote:If you have to swap TCs have you thout about getting one out of a TB so you can turn off awd all the time and have a low range? It would be more work but would be worth it if it were me.

I've played with the idea, but I don't want to deal with the wiring, I'm not a serious off roader and the height I'm at now seems to be perfectly acceptable and the all wheel drive is fine. I'm going to get a set of 17" spare rims and put some kind of aggressive tire on them for next winter

When I still had the 126 in my Bravada, I had to change encoder motors every three to four months. I got to the point that I always had a known good encoder motor in the rear floorboard, when I had to change mine, I'd take the old one to O'Reilly's and get a warranty replacement.

Since I installed the 226 case and rewired the vehicle to work with it (it thinks it's a TB), I haven't had any trouble with my encoder motor which is the one that was on the TC when I got it from the junkyard. I still have a spare though...